Design a realistic gas-powered assault rifle for a video game. It should feature a sleek, matte black metal body with a tapered barrel and adjustable foldable stock. Include KeyMod handguards, integrated suppressor, ergonomic trigger, and flip-up iron sights. Add detachable magazines and allow customization options. Emphasize wear and tear for realism, with authentic firing animations and effects. Aim for a modern military aesthetic with futuristic elements.